Electric protector mechanism for looms



July 5, 1949. c. R. KRONOFF ETAL 2,475,505

ELECTRIC PROTECTOR MECHANTSM FOR LOOMS Filed March 19, 1947 2 Sheets-Sheet 1 IN V E NTOR S CLARENCE R. KRONOFF VICTOR E SEPA V/CH ATTORNEY July 5, 1949. c, KRQNOFF ETAL 2,475,505

ELECTRIC PROTECTOR MECHANISM FOR LOOMS Filed March 19, 1947 2 Sheets-Sheet 2 INVENTORS CLARENCE R KRONOFF VICTOR E SEPAV/GH ATTORNEY Pawn-i, s, 1949 uni-rap STATES PATENT oral-cs ELECTRIC PROTECTOR MECHANISM FOR LOOMS Clarence B. Kronoi! and Victorl'. Sepavleh, Worcester, Mass assignors to Crornpton & Knowles Loom Works, Worcester, Mass a corporation of Massachusetts Application March 19, 1947, Serial No. 785,710

11 Claims.

This invention relates to improvements in electric protecting means for looms and it is the general object of the invention t6 control the loom motor by two switch means one of which is closed and opened by the shuttle and the other of which is closed independently of the shuttle during resula'rly recurring intervals. v

Inthe operation of a loom it occasionally happens that the picking mechanism will operate with reduced power, or may break, in which event the shuttle fails to box in proper time. This condition requires immediate stopping of the loom to prevent a warp smash. Various devices have been proposed heretofore to accomplish this general result, but many of them apply a stopping force while the motor is still running and connected to the loom, with the result that the stopping mechanism must not only overcome the momentum of the lay but also the driving power of the motor. It is an important object of our present invention to provide electric controls which stop the motor promptly in the event the shuttle fails to box on time.

The lay of a loom ordinarily reciprocates backwardly and forwardly and at the beginning of a normal flight interval the shuttle is picked at socalled top center when the lay is moving rearwardly and is boxed at the end of the interval when the lay is at or slightly forward of its bottom center position and is moving forwardly. If the shuttle fails to box properly at the end of the flight interval it is necessary to effect immediate stoppage of the lay. It is an important object of the present invention to relate the aforesaid two switch meansin such manner that one of them will maintain the motor circuit closed during the riformal flight interval and then act to open the motor circuit. If the shuttle is on time it will be able to close the other switch means before the end of the flight interval and thus keep the motor circuit closed. If, however, the shuttle is tardy it will not close its switch means until after the flight interval and the resultant interruption in continuity of the motor control circuit will cause motor and loom stoppage.

Under certain conditions it is desirable to reverse the loom under power in order to remove the shuttle from the warp shed, particularly if the lay is heavy. It is another object of the invention to provide reversing means for the motor controlled in such manner as to limit the amount of reverse motion which is possible. This second feature of the invention may be utilized to stop reverse motion of the loom when the sheds are wide open to permit easy removal of the trapped 2 shuttle. It is also desirable to stop reverse motion beforethe picking arm can move backwardly far enough to damage. the picking cam.

with these and other objects inview which will appear as the description proceeds, the invention resides in the combination and arrangement of parts hereinafter described and set forth.

In the accompanying drawings, wherein a convenient embodiment of the invention is set forth,

Fig. 1 is a front elevation of a m equipped with the invention.

Fig. 2 is an enlarged front elevation of one of the shuttle controlled switches showing the latter in the open position to which it is moved when the shuttle is moved out of the adjacent shuttle box,

Fig. 3 is an end view looking in the direction of arrow 3, Fig. 2,

Fig. 4 is an enlarged side elevation looking in the direction of arrow 4, Fig. 1,

Fig. 5 is a detailed side elevation of one of the picking mechanisms looking in the direction of arrow 5, Fig. 1,.

Fig. 6 is a diagrammatic view of electric circuits of a type which can be employed with the invention to effect sudden stoppage of the motor in the event the loom protects.

Referring particularly to Fig. the loom frame In is provided with a lay which is rocked backwardly and forwardly in known manner. Top and bottom, shafts l2 and ii are connected by ears and ii of such size as to cause the bottom shaft to rotate once every other pick of the loom. The top shaft completes a rotation every pick of the loom and supplies the power by which the lay is reciprocated. The lay is mounted on lay swords it carried by a rocker shaft l1, and a hand rail It connects the tops of the lay swords.

The lay is provided with shuttle boxes 20 and 2| located respectively at the right and left ends of the lay. Picker sticks 22 operate in alternation to propel the shuttle 8 back and forth across the lay from one box to the other. One of the pick-' ing mechanisms is shown in Fig. 5 and includes an arm 25 on bottom shaft [3 for operation of a cam 26 on a picking shaft TI extending backwardly and forwardly in the loom. During normal running of the loom picking arm 25 first engages the low side of cam 26 and then progresses therealong to the high side, thereby depressing the cam and rocking shaft 21 in a counter-clockwise direction as viewed in Fig. l. The picker shaft has a picking arm 28 connected to a sweep stick 29 to give the picker stick a picking stroke when shaft 21 rocks. 'After arm 25 passes the cam 25' the latter returns to its normal position with the high side thereof near the arm.

If shuttle S is to be picked to the left as viewed in Fig. 1 the picker mechanism already described will move the picker stick to the left when the lay reaches top center,.or approximately its midposition when moving-rearwardly.. The picked shuttle then travels across the lay toward box 2| as the lay continues to move backwardly and also during a part of the ensuing forward move- .ment of the lay. Ordinarily the shuttle will complete'its travel in the normal flight period or interval and will enter box 2| on time. If for any reason the shuttle should fail to reach box 2| on time part of it at least will be in-the warp shed and cause a warp smash unless forward motion of the lay is stopped.

The loom is operated by a motor M which may be connected to the bottom shaft I3 by means of belts 55 wrapped around a pulley 3| secured to shaft I5. We do not contemplate use of the customary clutch and shipper mechanism, but rely upon a permanent connection between the motor and the loom for operation of the latter whenever the motor is running. If the motor is stopped abruptly it will act through the belts 35 and gears l5 and H to stop the lay.

Of the two previously mentioned control switch means one is operated by the shuttle and the other by the loom. The shuttle control switch means includes two switches designated generally at SR and SL in Fig. 1 for the right and left hand sides of the loom. Each switch is adjacent its corresponding shuttle box and has a part which is moved by the shuttle as the latter enters and leaves the shuttle box. Both of these switches are the same except that they are of opposite hands, and a description will be given of but one of them, namely, the switch SL adjacent to box 2|.

The left end of handrail l5, see Fig. 2, has secured thereto a plate 55 to which a support 55 is secured in adjustable angular position by stud 31 which has a lock nut 38 to hold its adjustment. A stud 45 extends forwardly from support 55 and has pivotally mounted thereon a carrier arm 4| and a switch casing 42. The latter has upper. and lower spring contacts 43 and 44 which in effect constitute a switch which is closed when contacts 43 and 44 engage each other.

Arm 4| is provided with a stud 45 on which is pivoted an operating lever 45 having at its upper end a finger 41 extending over the casing 42 and to the right of an abutment or stop 45 on the casing. The lower end of lever 45 is provided with a second finger or pin 55 which extends along the left side of a shuttle engaging operating arm 5| pivoted on stud 45. A look arm 52 also pivoted on stud 45 extends upwardly and is normally drawn to the right as viewed in Fig. 2 by a tension spring 53 extending betweenthe support 55 and the upper end of lock arm 52.

A compression spring 55 between carrier arm 4| and switch casing 42 tends normally to separate these parts, and a torsion spring 55 around stud 45 has one end in engagement with arm 4| and the other end held by an adjustable collar 51 on stud 45. Spring 55 normally tends to hold arm 4| down against a stop 55 on the left end of stationary support 35.

In Fig. 2 the parts are shown in the position they assume when the shuttle is in flight toward box 2|, casing 42 being up due to action of spring 55 and the spring contacts 43 and 44 beingout of engagement with each other to maintain switch 4 BL open. The resilience of contact 44 keeps a small plunger 5| in down position against arm 4| as shown in Fig. 2. v

As the shuttle enters the box its upper advancing end will engage arm 5| and move the latter to the left, thereby moving pin 55 in sucha direction as to turn lever 45 clockwise andl'ower stud 41 the effect of which is to swing casing 42 downwardly around stud 45. Plunger 5| is prevented from moving downwardly by its engagement with arm 4| and the contacts 42 and 44 consequently engage each other to close switch 8L.

Lock'arm 52 is provided with a detent 52 which is moved over the left end of casing 42 by spring 55' when the casing is depressed by stud 41. The casing is thereforelocked in down position and switch SL remains closed so long as the shuttle is in box 2|.

When the shuttle is picked out of box 2| it engages and moves arm 5| to the right as viewed in Fig. 2, thereby causing a lifting surface 53 thereon to engage the lower end 54 of lock arm 52 and rock the latter in a counter-clockwise direction as viewed in Fig. 2 to move detent 52 to the left away from holding position relatively to casing 42. The latter thereupon rises under action of spring 55 and the contacts 42 and 44 separate to open switch SL.

Switch SR at the right side of the loom is similar to switch SL except that it is reversed and is closed by right hand movement of the shuttle into box 25 and is opened by left hand movement of the shuttle out of box 25.

From the matter thus far described it will be understood that whenever the shuttle enters one or the other of the boxes 25 or 2| the adjacent switch will be closed, but when the shuttle is picked out of the box the switch will be opened. It is apparent that while the shuttle is in flight both switches SR and SL will be open and closure of one or the other of them will depend upon arrival of the shuttle at the corresponding shuttle box, or at least upon arrival at given points along the lay near the shuttle boxes.

The second of the aforesaid motor controlling switch means is shown in Fig. 4 and operates in time with the loom independently of the shuttle.

This control includes a disk cam 55 secured to the bottom shaft [5 and completing a rotation in the direction of the arrow every second pick of the loom. One half of the disk therefore corresponds to one pick of the loom. The disk has two inclines each rising from a low dwell 51 to a higher area 55 which gradually declines to a dwell. Engaging this disk is a roll 59 rotatable on an arm 15 pivoted on a switch WS. The latter is closed by a plunger 1| whenever roll 59 engages a dwell 51, but is open when an incline 55 engages the roll and moves it away from shaft i3. As the cam continues to turn the roll 59 returns gradually to the other dwell 51.

Switch WS is thus seen to be controlled by the loom and will be closed during the aforesaid normal flight interval, or from a time shortly prior to picking of the shuttle out of either box until the time has arrived in the loom cycle when the shuttle should be boxed at the opposite side, or at least have reached a given point along the lay near the box. Switch WS is then opened, but if the shuttle is on time switch SR or SL will be closed before switch WS opens. If, on the other hand, the shuttle is tardy, switch WS will open before one or the other of the switches SR.8L closes, and there will be a period during which all three of these switches are open. This is the condition which as described hereinafter will bring about sudden stoppage of motor M. When the shuttle is running properly there will be no time during which all three switches are open, and motor M will continue to run, control of it being taken over by a shuttle switcgbefore switch WS relinquishes its control. It will be understood that each complete rotation of disk 85 provides the aforesaid controls of switch WS for two successive picks of the loom.

The condition under which all three of the switches SR, SL and WS are open simultaneously can be utilized to control any one of several circuit means for stopping the motor M. The circuits shown in Fig. 6 are illustrative of electric means which can accomplish this result, but we do not wish to be limited to such circuits, nor do we claim the details of this circuit means. The right hand part of Fig. 6 shows the manual or low voltage controls for the motor, while the left hand part illustrates the power connections which are controlled by the right hand circuits.

The motor M may be of the three phase alternating current type having a squirrel cage rotor 18 and a stator H the leads of which are brought out as indicated at the lower left hand part of Fig. 6 to permit the motor to be started first with a delta connection of its stator windings to give high starting torque, and then change to Y connections for continued running. The delta switches are designated at D and the Y connections by switches Y. This mode of converting from delta to Y operation is desired when the motor is connected directly to the loom without 1 the use of a clutch, as herein contemplated.

The three alternating current power lines 15, I6 and I1 may be relatively high voltage such as is customary in the operation of textile motors, and two of these wires excite the primary I8 of a transformer 19 the secondary 88 of which supplies reduced voltage, such as 110 volts, for the control circuits. The loom is provided with a start switch ST and a stop switch SP, and the previously described switches SR and SL and WS are connected in parallel.

When the loom is at rest and it is desired to start weaving, the shuttle will be in one or the other of the boxes 28 or 2|, and the lay will in all likelihood be in-such position that switch WS will be closed. In Fig. 6 it is assumed that switches WS and SR are closed and switch SL open with the shuttle at the right side of the loom. Stop switch SP will be closedunder these conditions so that depression of the start switch ST will cause current to flow from the secondary 88 through a control relay CR. When this relay is energized it efiects closure of switch 8| the result of which is to energize a relay 82 which closes the switches 83 and 84 to shortcircuit half wave rectifiers 85 and 88, respectively, and simultaneously open switches 81 and 88 to disconnect the negative side of condensers 88 and 88 from wire 9| leading from the master motor switch MS to stator II.

As soon as control relay CR is energized it also closes switches 95 and 95' which connect one side of secondary 88 with a control relay DS for closure of the D switches corresponding to the delta connection of the motor. Closure of switch 95 also connects secondary 88 to a single wave rectifier 98 connected directly to the master switch relay 91 to close the motor master switch MS. The motor therefore starts with a delta connection and with the rectiflers 85 and 88 short- 6 circuited by switches 88 and 84, respectively, and with switches 81 and 88 open.

Connected also to the rectifier 88 is a resistance 88 leading to parallel circuits one of which includes a condenser 88 and the other of which includes a switch I88 closed by relay 81 and a transfer relay TR. which has, a relatively high resistance. Condenser 88 is normally discharged and requires an appreci?ble time to become fully charged during which t prevents operation of relay TR. When condenser 88 fully charged, however, it no longer drains thecurrent which flows through the resistance 88 and relay TR. will close switch I8I to operate relay I82 to close switches Y and open switch I88 DS to open switches D.

As previously mentioned, it is essential that the lay be stopped suddenly it the shuttle should fail to box properly, and this result is accomplished by causing direct current to flow through the stator of the motor when protection is to be eifeeted. The direct current is supplied by the rectifiers and 88 and the condenser 88 and 88 smooth out the pulsations of unidirectional cur rent from the rectiflers to give a continuous strong non-rotary magnetic field in the motor.

In order to enable the rectiflers 85 and 88 to operate it is necessary to open switches 88 and 84 and close switches 81 and 88. This is accomplished either by pushing the stop button SP,

or by having all three switches SR, WS and SL open at the same time to break the circuit on the control relay CR. Whenever this latter condition arises relay CR is deenergized and switches 8| and 85 open. Opening of switch 8| acts by release of relay 82 to open switches 83 and 84 andclose switches 81 and 88, thereby enabling the rectiflers 85 and 86'to deliver unidirectional current to the motor. This direct current flows for a short time only and brings the motor to a sudden stop in about the same time that opening of switch and its release of relay 81 causes opening of the master switch MS. The motor is therefore stopped promptly and disconnected from the power lines 'I5'l1. By reason of the direct connection between the motor and the lay the latter is stopped abruptly to prevent the lay from moving the shuttle forwardly to cause a warp smash.

In the lighter types of loom it may be desirable to provide the loom with a light holding brake HIB which can be overpowered by the weaver when turning the usual hand wheel in reverse direction. This brake is oil when switch MS is closed, but is on when that switch opens. When the invention is applied to heavier looms. such as those used in the manufacture of carpets, it is des rable to be able to reverse the loom under power, but it will be understood that the amount of reversal should be limited to prevent picking arm 25 when moving reversely from striking the high side of cam 28. It will also be apparent that it will be suillcient so far as withdrawal of the shuttle from the shed is concerned if reverse motion is stopped automatically when the warp sheds are wide open. This second feature of our invention is illustrated in Figs. 4 and 6. A second disk I85 is mounted on bottom shaft I8 and has two notches I86 for cooperation with a plunger I81 slidably mounted in a stand I88 on pivot I 88' supported from the floor. Secured to the plunger is a conical collar I88 held to the left as viewed in Fig. 4 by a compression spring II 8. The collar I89 is normally in the position shown in Fig. 4 and perto release relay as will be described hereinafter, disk I turns in the direction opposite to that indicated by the arrow in Fig. 4 and one or the other of the notches I08 moves plunger I01 to the right, thereby causing conical collar I09 to depress arm H2 and act through plunger H3 to open switch Hl.

Referring to Fig. 6, the leads from master switch MS are connected in reverse order and through resistances H5 to a reverse switch RR. A control reverse relay H6 for switch RR is connected to the secondary 80 by a circuit which includes switch H4 and a normally open manually closable switch II'I.

After the loom has been stopped as already described, and assuming that the invention is applied to the type of loom on which power reversal is desirable, switch III will be depressed and relay II6 will be energized to close switches RR "and H8, thereby effecting reverse motion of the motor to swing the lay backwardly from the fell of the cloth to permit extraction of the trapped shuttle. If switch II! should by oversight be depressed too long one of the notches I06 will eventually push plunger I01 to open switch H the result of which deenergizes reverse relay I IS. The reverse switch RR thereupon opens to prevent further backward movement of the motor, and switches H8 release relays DS and 02.

Start button ST is bridged by a switch I20. When relay OR is energized by closure of the start switch it closes switch I20 and the latter remains closed so long as the relay is energized. If the relay is deenergized by opening of the stop switch, or simultaneous opening of switches SL, SR and WS, switch I20 will open. It is for this reason that relay CR will not be reenergized upon closure of loom operated switch WS when the weaver turns the loom back to take the trapped shuttle out of the warp shed. Switch I20 has no control over the reversing circuit and the fact that it is open will not interfere with reversal of the loom under power.

If the lug strap of either picker stick should loosen and fall, thus increasing the leverage on the stick, the shuttle will be picked with a force stronger than usual and is likely to rebound after being boxed. In that event the adjacent shuttle switch SL or SR will be opened during the normal period of opening of the loom switch WS, and the loom will be stopped.

From the foregoing it will be seen that we have provided electric protecting means for looms operated in such manner as to exercise two separate controls over the motor controlling circuits. One of these controls is derived from switches SR and SL and is under control of the shuttle,

while the other control is derived from disk 00 and is under control of the loom. When the periods of closure of these controls overlap, a condition existing when the shuttle is operating properly, there is no interruption in the control circuits for the motor and the latter continues to run to operate the loom pick after pick. If, on the other hand, the shuttle should be tardy, switch WS is open before closure of switch SR or SL, and the motor control circuits are interrupted to eilect instant loom and motor stoppage. The switches at the shuttle boxes are made in such manner that they are closed upon entry 01' the shuttle into the box and opened when the shuttle is picked out of the box, and these two switches will normally be open while the shuttle is in flight. Furthermore, we provide for reversal of the motor under such control as will allow a limited amount only of reversal. Disk I" can be so set with respect to the loom that when either notch I06 pushes plunger I01 switch ill will open with the lay on approximate back center. or with the sheds wide open. This control also occurs before the picking mechanism by reversal can cause damage by engagement of arm 20 with the high side of cam 28.

Having thus described our invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and we do not wish to be limited to the details herein disclosed, but what we claim is:

1. In electric protecting means for a loom operating with a shuttle, an electric motor driving the loom, a switch closed during a shuttle ilight interval but open at the end of the interval, a second switch closed by the shuttle prior to the end of said interval if the shuttle is on time and remaining closed independently of the shuttle but open simultaneously with the first switch it the shuttle is late, and electric circuit means controlled by said switches efiective to cause continued running of the motor so long as one or the other of said switches is closed but effective to cause motor stoppage if said switches are both open simultaneously.

2. In electric protecting means for a loom operating with a shuttle, an electric motor driving the loom, a switch closed each pick of the loom for an interval ending with the end of the normal time required for flight of the shuttle but open after said interval, a second switch closed prior to the end of said interval if the shuttle is on time and remaining closed independently of the shuttle but open simultaneously with the first switch if the shuttle is late, and electric control circuit means for the motor controlled by said switches eifective to cause continued running of the motor so long as one of said switches is closed before the other switch opens but effective to stop the motor if both switches are open simultaneously.

3. In electric protecting means for a loom 7 operating with a shuttle, an electric motor driving the loom, a switch closed each pick 01' the loom for an interval ending with the end of the normal time required for flight of the shuttle but open after said interval, a second switch closed prior to the end of said interval i! the shuttle is on time and remaining closed independently of the shuttle but open simultaneously with the first switch if the shuttle is late, and electric control circuit means for the motor including said switches eiIective to cause continued running of the motor if the second switch is closed prior to the end of said interval but eflective to stop the motor if said second switch is open at the end of said interval.

4. In electric protecting means for a loom having a shuttle moving along a lay, a motor running to operate the loom, electric circuit means controlling the motor eflective when remaining closed to cause running oi the motor but effective if opened to stop the motor, a part independent of the shuttle moved regularly by the loom during loom operation, a switch for said circuit means closed by said part for a given interval only of the loom cycle, and a second switch remaining open after said interval if the shuttle fails to reach a given point along the lay before the end of saidinterval, but being closed by the shuttle if the latter reaches said point before the end of said interval and remaining closed independently of the shuttle, each switch when closed closing said circuit means, and said switches when open simultaneously opening said circuit means.

5. In electric protecting means for a loom having a shuttle in flight along a lay toward a shuttle box, a motor running to operate the loom, normally closed electric control circuit means which when remaining closed causes continued operation of the motor but efiective ifopened to stop the motor, a switch closed during a given portion only of the loom cycle to close said circuit means, a second switch mounted on the lay independently of but adjacent to said shuttle box open at the beginning of the flight of the shuttle but closed by the shuttle when the latter reaches a given point in the travel thereof along the lay toward the shuttle box, said second switch if closed prior to the end of said portion of the loom cycle maintaining the circuit means closed to effect continued running of the motor, said second switch if remaining open after the end of'said portion of the loom cycle opening said circuit means to stop the motor.

6. In electric protecting means for a loom operating with a shuttle, an electric motor driving the loom, two switch means, electric circuit means including said switch means causing continued running of the motor so long as one or the other of said switch means is closed but causing stopping of the motor if both switch means are open simultaneously, and means operated by the loom causing one of said switch means to be closed during a given flight interval in the loom cycle and to be open at the end of said interval, the second switch means being normally open during shuttle flight but being closed by the shuttle prior to the end of said interval if the shuttle is on time and remaining closed independently of the shuttle, said second switch means being open simultaneously with the first switch means if the shuttle is late and fails to close the second switch means prior to the end of said interval.

7. In electric protecting mechanism for a loom having a shuttle box and a ,shuttle in flight during part of one pick of the loom cycle and in said box during the remainder of said pick and then picked out of the box on the next pick of the loom, an electric motor driving the loom, an electric switch closed at regularly recurring intervals during loom operation when the shuttle is in flight, a switch adjacent to but independent of said shuttle box open when the shuttle is in flight and closed when the shuttle is in said box, and electric control circuit means for the motor including said switches efl'ective when remaining closed to cause continued running of the motor but effective if interrupted to stop the motor, the shuttle when running normally closing the second named switch before the first named switch opens at the end of the interval of said one pick and opening the second switch after the beginning of the interval of the next pick to effect continued closure of said control circuit means, the second switch unless closed from a time prior to the end of the first interval until after the beginning of the second interval causing an interruption of said circuit means to effect stoppage of the motor.

8. In electric protection means for a loom having a lay and operating with a shuttle having alternating periods of flight and rest in a shuttle box, an electric motor driving the loom, electric control circuit means for the motor which when remaining closed efl'ects continued running of the motor but if interrupted causes stoppage of the motor, and two switch means controlling said circuit means, the first of said switch means being loom operated and closed periodically during intervals corresponding to' flight of the shuttle and the other switch means being mounted on the lay independently of the shuttle box and closed by the shuttle and remaining closed during periods of rest of the shuttle, the shuttle when running normally closing the second switch means before opening of the flrst switch means on any given pick of the loom and the first switch closing prior to opening of the second switch means incident to picking of the shuttleon the next pick of the loom to effect continued closure of said circuit means, said first and second switch means when opened simultaneously effecting interruption of said circuit means.

' 9; In electric protection means for a loom having a lay with the shuttle box at each end thereof and a shuttle picked back and forth from one shuttle box to the other shuttle box and having periods of flight alternating with periods of rest in one or the other of said shuttle boxes, an electric motor driving the loom, electric control circult means for the motor which when remaining closed eil'ects continued running of the motor to drive the loom but which when interrupted causes stoppage of the motor and the loom, a loom controlled switch closed during an interval of each pick of the loom corresponding to normal flight of the shuttle and open during normal periods of rest of the shuttle, and a shuttle switch mounted on the lay independently of the shuttle box and adjacent each shuttle box, each shuttle switch being open during flight of the shuttle and the shuttleswitch adjacent to the shuttle box toward which the shuttle is moving being closed prior to the end of said interval ,ii the shuttle is on time but remaining open after the end of said interval if the shuttle is late, said loom and shuttle switches when having overlapping periods of closure eflecting continued closure of said circuit means but effective when open simultaneously to interrupt said circuit means,

opening at the end of the interval, a shuttle operated switch mounted on the lay independently of the shuttle box and closed by the shuttle as the latter enters the shuttle box but opened by the shuttle if the latter rebounds from the shuttle box, said loom operated switch and said shuttle operated switches having overlapping periods of closure when the shuttle is running normally and enters the shuttle box on time but being simultaneously open if the shuttle is running abnormally and is late, an electric motor driving the loom, and electric control circuit means for the motor remaining closed to effect continued running of the motor when the periods of closure of the loom operated switch and the shuttle operated switches overlap but effective to stop the motor if said loom controlled and shuttle controlled switches are opened simultaneously due either to late closure of the shuttle controlled switch or opening of the latter by rebounding oi the shuttle while the loom controlled switch is open.

11. In electric protecting mechanism for a loom having a shuttle box toward which a shuttle is moving, an electric motor driving the loom, an electric control circuit for the motor which when remaining closed eii'ects continued running of the motor but which when opened eflects motor stoppage, a loom controlled switch closed to close the circuit during a given interval of the loom cycle and then open for the remainder of the cycle, a shuttle controlled switch mounted independently of the shuttle box closed to close the circuit means by the shuttle when the latter enters the shuttle box and opened by the shuttle when the latter leaves the shuttle box; the shuttle when entering the shuttle box on time closing the shuttle operated switch before opening of the loom operated switch to eflect continued closure of said circuit means, and the loom operated switch then closing before the shuttle leaves the shuttle box to effect further continued closure of said circuit means, said shuttle operated switch it being open at any time during which the loom operated switch is open eflecting opening of said circuit to stop the motor.

CLARENCE R. KRONOFI".

VICTOR F. SEPAVICIL REFERENCES CITED The following reierenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 905,131 Bacon Dec. 1, 1908 FOREIGN PATENTS go Number Country Date 406,194 Great Britain Feb. 22, 1934 458,289 Great Britain Dec. 16, 1936 491,248 Great Britain 15118.29. 1938 

